HesapHanem

Calorie (15 °C) to Joule Converter

Enter a value and choose a conversion direction.

Result

1,046.3750 J
1 cal₁₅ = 4.1855 J
250.0000 cal₁₅

How it is calculated

The tool uses one fixed factor, 1 cal₁₅ = 4.1855 J. Choosing the calories-to-joules direction multiplies your value by 4.1855; choosing joules-to-calories divides by 4.1855. The result is shown with 4 decimals, together with the rate used and a line that repeats your input in its own unit so you can see what was converted. Here a calorie means the small calorie (1 cal), the 15 °C version, not the kilocalorie (kcal, Calorie) of food labels, which is 1,000 times bigger. The tool does not block negative numbers, and a negative energy is just converted with the same factor. Other calorie definitions use slightly different factors, so do not mix them with this one.

Worked example

A reading in an old physics table is 250 cal₁₅ and you need joules. With the calories-to-joules direction: 250 × 4.1855 = 1,046.3750 J. The reverse line repeats 250.0000 cal₁₅. For comparison, using 4.184 J per calorie would give 1,046.0000 J, a difference of 0.375 J, which only matters in precise work. Going the other way, 1,000 J ÷ 4.1855 = 238.9201 cal₁₅.

Try this example →

Common mistakes

  • Entering kilocalories (food Calories) as calories. 250 kcal is 250,000 cal, so the joule result would come out 1,000 times too small unless you multiply by 1,000 first.
  • Choosing the wrong direction. If you meant to convert joules but left the default, 100 J is multiplied by 4.1855 instead of divided, giving 418.55 instead of 23.8920.
  • Using this factor for nutrition labels. Food energy normally uses a different calorie definition, so the result can differ slightly from a label's kJ figure.
  • Mixing calorie definitions in one calculation. The 15 °C, thermochemical and International Table calories differ by a few hundredths of a percent, so convert everything with the same factor.
  • Treating rounded output as exact. The display stops at 4 decimals, so for chained calculations keep more digits.

About this calculator

The “15 °C calorie” (cal₁₅) is one of several historical, slightly different definitions of the calorie: the energy needed to raise the temperature of 1 gram of water from 14.5 °C to 15.5 °C at standard atmospheric pressure, as measured directly by calorimetry rather than defined by convention. It’s distinct from the thermochemical calorie (exactly 4.184 J) and the International Table calorie (4.1868 J) used in nutrition labeling — the differences are small, around 0.03%, but matter in precise calorimetry and older scientific literature.

This calculator converts between cal₁₅ and joules using the accepted equivalence 1 cal₁₅ = 4.1855 J, in either direction, which is the figure needed when digitizing or cross-checking older thermochemical data, physics textbooks, or calorimeter calibration records that specify energy in the 15 °C calorie rather than the modern SI joule.

Was this helpful?

You can pick up to 3 reactions.

Comments (1)

  • Editorial team

    This is the small calorie, not the food-label Calorie. A 100 kcal snack is 100,000 of these calories, which is 418,550 J with the 15 degree factor used here. Other calorie definitions differ in the fourth digit, so keep one definition throughout a calculation. Which calorie definition does your source use: thermochemical, international table or the 15 degree one?

Popular calculators

Loan Calculator

Monthly payment, total interest and full amortization schedule.

Percentage Calculator

Percent change, percent of, and ratio calculations.

Discount Calculator

Calculate final price, savings, and discount amount.

BMI Calculator

Body mass index from height and weight (metric or imperial).

Age Calculator

Compute your exact age in years, months and days from a birth date.

Compound Interest Calculator

Calculate the final amount and interest earned with compounding.

All Calculators